I've had this car for a month. It's a 2002 Monte Carlo with only 64K miles on it. When I got it, it ran perfect until today. I was cruising down the interstate and everything was fine and suddenly, the engine light came on and the engine was running eratic and misfiring and I lost speed until it wouldn't go any faster than 50. I pulled off the interstate and looked under the hood and the engine was vibrating terribly.

So I took the thing to Autozone and had them read the codes and they said the probable causes were:

"Purge or vent solenoids defective"
"check connector and wiring"
"fuel saturated vapor canister"
"failed EVAP vent solenoid"

Of course, having driven older cars all my life, this is all greek to me, so I took it to a trusted mechanic friend who couldn't believe that any emissions control issue such as the EGR or PVC valve would cause a symptom that looked and felt like misfiring. Especially since it happened so suddenly. But he checked what he could and couldn't really find an answer. Then I asked if a clogged fuel injector could cause that. He said it probably could, so I put fuel injector cleaner in the car, and it SEEMS to be running a LITTLE better, but not much.

Any help would be appreciated. Took it on the road after the injector cleaner and it did get up to 70 but would not accelerate any faster, and at stops, engine runs eratic and misfires badly. Acceleration is sluggish at best, even with the pedal pressed all the way down.

I love this car and I'm terribly disappointed that this would happen after a month of owning it. Hope someone can shed some light on this.

EDIT:////

When I fired it up this morning, 7/2/10, it still felt like it was misfiring, but it was FAR more responsive and the acceleration was as it has always been. However, as I drove it, it became more and more sluggish. My drive to work is only 15 minutes and in that time, it went back to like it was yesterday. This MC is an LS with 3.4 V6 Sure hope someone can help out with this one.

 

WOW. Thats crazy. I do have one question. Is it an SS or LS?

I am sure that in the morning a few guys will be able to help you. Good luck.

 

Nobody knows?!

 

i would check each injector and spark plug to begin with, possibly check the wires also.

 

have you pulled your spark plugs to see if there is any fouling? check the plug wires?

 

spark plugs, ignition coils,, probobly something in that range like they were saying. i had a suzuki that liked to blow ignition coil packs every 30k miles, it was a bitch. idk how these cars are, probobly alot cheaper than the 250$ ignition coil packs for that pos suzuki i had lol

 

I'm having the car checked out by a friend who is doing a compression test on the #1 cylinder. He's doing that because I took it to firestone yesterday and they told me that I had a clogged cat converter AND that I "cooked the #1 cylinder" and I will require a new engine. Naturally, this is not something I wanted to hear and that's why I took it to my friend's house. He wanted to do a compression check.

As far as I know, all the plugs are fine. I guess I should have checked that out myself, but i didn't think about it.

A new engine? Are they serious or are they just a tire store trying to get some money out of someone they THINK doesn't know crap about cars?

 

i never take my car to a large corpation machanic, dont you know any local machanics that you trust? i take all my cars to a family machanic, i get great rates, i only pay like 15$ an hour on any work, and get dealer direct pricing, even though most parts i'll buy my self. i doubt you burned up your engine, theres no way you'd of done that on such a low milage car with out beating it pretty hard.

 

That's how my mechanic and I feel about it. My friend who is looking at it is a trusted mechanic, but this problem just has him stumped.

 

Does it idle OK? If the idle is rough, unplug the MAF. If the car idles fine, you have a faulty MAF sensor. Although your symptoms seem like a clogged cat.